• Title/Summary/Keyword: Multiple Performance Characteristics

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Investigation of decontamination characteristics of a serial multiple pool scrubber system for consequence mitigation of severe accidents

  • Hyeon Ho Byun;Man-Sung Yim
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4585-4600
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    • 2022
  • A pool scrubber is often used as a wet-type design to mitigate the consequence of a severe nuclear accident. While studies indicated higher decontamination performance of a deeper pool, utilizing a very tall pool can be problematic due to potential structural stability and water backflow issues. This study proposes, as an alternative to a single pool system, a pool scrubber system composed of serially connected multiple pools with lower heights. Since large fraction of aerosol removal takes place in the injection region, serially connected pool scrubber system is expected to enhance the overall decontamination capability of a pool scrubber system. To support the analysis of the proposed system's decontamination capability, a new computer model was developed in the study to describe the bubble size dependent effect on aerosol removal including the effect of pool residence time. The accuracy of the new model was examined against experimental data for its validation. The proposed scrubber system composed of serially connected multiple shorter pools is found to have much improved decontamination performance over the current single pool system design.

A Study on the Factors Affecting Work Performance among Systems Librarians in Academic Libraries (대학도서관 시스템 라이브러리언의 작업성과를 높이는 요인에 관한 연구)

  • Bang Jun-Phill
    • Journal of the Korean Society for Library and Information Science
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    • v.32 no.3
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    • pp.231-250
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    • 1998
  • The purpose of this study was to investigate factors affecting work performance among systems librarians in Korean academic libraries. The factors were divided in three categories: Job characteristics, organizational characteristics, and individual characteristics. Data from questionnaire were analyzed using the SPSS for windows. Multiple regression analyses were performed on three sets of variables related to the hypotheses of the study. The result of the analysis Identified the folowing factors : Job characteristics which affect work performance among systems librarians in academic library are autonomy, task significance, skill variety, and feedback from supervision. Organizational characteristics which affect work performance are job security, capability of automation systems, coworkers. Individual characteristics which affect work performance are growth need strength, knowledge, and systems librarian experience.

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The Effect of Environmental and Organizational Characteristics of the Fashion Companies on Continuous Acceptance Intention and Performance of the Internet Business (패션 기업의 환경특성 및 조직특성이 지속적인 인터넷 비즈니스 수용의도 및 성과에 미치는 영향)

  • Lee, Eun-Jin
    • The Korean Fashion and Textile Research Journal
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    • v.11 no.3
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    • pp.427-436
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    • 2009
  • The purpose of this study is to analyze whether environmental and organizational characteristics have an effect on continuous acceptance intention and performance of the internet business in fashion companies. A survey was conducted from January 15 to February 15 in 2009, among members of fashion companies carrying out internet business. The data was collected with 288 subjects, the statistical analysis methods were frequency analysis, factor analysis, reliability analysis and multiple regression analysis. The results of this study were as follows; First, environment characteristics(internal pressure, external pressure) and organizational characteristics(chief executive officer, capacity of the organization and future directivity) of the fashion companies had an effect on continuous acceptance intention of the internet business. Second, environment characteristics and organizational characteristics of the fashion companies had an partially effect on performance of the internet business. Third, elevation of the business, customer relationship improvement and raise the market reactivity in performance factors of the fashion companies had an effect on continuous acceptance intention of the internet business.

Performance of Distributed MISO Systems Using Cooperative Transmission with Antenna Selection

  • Park, Jong-Hyun;Kim, Jae-Won;Sung, Won-Jin
    • Journal of Communications and Networks
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    • v.10 no.2
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    • pp.163-174
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    • 2008
  • Performance of downlink transmission strategies exploiting cooperative transmit diversity is investigated for distributed multiple-input single-output (MISO) systems, for which geographically distributed remote antennas (RA) in a cell can either communicate with distinct mobile stations (MS) or cooperate for a common MS. Statistical characteristics in terms of the signal-to-interference-plus-noise ratio (SINR) and the achievable capacity are analyzed for both cooperative and non-cooperative transmission schemes, and the preferred mode of operation for given channel conditions is presented using the analysis result. In particular, we determine an exact amount of the maximum achievable gain in capacity when RAs for signal transmission are selected based on the instantaneous channel condition, by deriving a general expression for the SINR of such antenna selection based transmission. For important special cases of selecting a single RA for non-cooperative transmission and selecting two RAs for cooperative transmission among three RAs surrounding the MS, closed-form formulas are presented for the SINR and capacity distributions.

A study on the engine performance in a multiple spark ignition engine (다회수 스파크 점화기관의 기관성능에 관한 연구)

  • 이성열;한병호
    • Journal of the korean Society of Automotive Engineers
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    • v.10 no.4
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    • pp.66-74
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    • 1988
  • The ignition quality of ignition system is influenced by spark energy, discharge pattern of spark energy and spark duration. In this paper, the characteristics of multiple spark ignition system have been investigated for various number of spark and spark interval. The results, which were compared with those obtained with a standard single spark ignition, show that engine output is increased, and lean misfire limit is extended with the multiple spark ignition system. The most effective number of spark at the most effective spark interval that are determined by engine performance test, were 6 times spark at 0.02ms spark interval. For the above condition of spark, engine torque was increased about 20% comparing with conventional ignition system and lean misfire limit was extended to air-fuel ratio 22.5:1. This study researched the rate of heat release and quantity of heat release influenced by a condition of spark on the mass burned in order to investigate the relationship between the rate of mass burned and number of spark times.

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Performance Improvements of Energy Detector for Spectrum Sensing in Cognitive Radio Environments: Verification using Multiple Antennas (인지무선환경에서 스펙트럼 센싱을 위한 에너지 검출기의 성능개선: 다중안테나를 이용한 확인과정)

  • Baek, Jun-Ho;Oh, Hyeong-Joo;Lee, Jong-Hwan;Hwang, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.4
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    • pp.38-42
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    • 2008
  • In this paper, we propose a new structure for spectrum sensing which employs multiples energy detectors in multiple antenna system in order to improve its reliability. The performance is analyzed by simulation and compared to that of the conventional energy detector. The simulation results shows that the performance of the proposed scheme is much better than that of the conventional one. Additionally, the performance of is described in terms of ROC curve.

Importance-Performance Analysis of Restaurant Meal Replacement (RMR) Selection Attributes According to Food Involvement Type (음식관여도 유형에 따른 레스토랑 간편식 선택속성 중요도-수행도 분석)

  • Seung Gyun Choi;Wan Soo Hong
    • Journal of the Korean Society of Food Culture
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    • v.38 no.6
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    • pp.402-414
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    • 2023
  • This study evaluated the consumers' demands and points of improvement for restaurant meal replacement through importance-performance analysis by the restaurant meal replacement segment market using food involvement. The results were as follows. First, after segmenting the restaurant meal replacement market using food involvement, it was classified into three markets (multiple involvements, exploration-oriented, and product quality-oriented). Second, an analysis of the importance of restaurant meal replacement selection attributes revealed taste, sanitation, quality, freshness, price, saving time, texture, ingredients, preparation process, and quantity to be highly important. An analysis of the differences according to the market type revealed the multiple involvement type to be more important than other groups, considering the restaurant meal replacement selection attribute element. Third, an analysis of the importance-performance analysis of restaurant meal replacement selection attributes revealed that quantity and price as the selection attributes that needed to be improved first in all three markets. In addition, in the multiple involvement type, food additives appeared as a selection attribute requiring priority improvement, revealing the characteristics of a market that cares about diet and health.

Multiple Object Tracking Using SIFT and Multi-Lateral Histogram (SIFT와 다중측면히스토그램을 이용한 다중물체추적)

  • Jun, Jung-Soo;Moon, Yong-Ho;Ha, Seok-Wun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.9 no.1
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    • pp.53-59
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    • 2014
  • In multiple object tracking, accurate detection for each of objects that appear sequentially and effective tracking in complicated cases that they are overlapped with each other are very important. In this paper, we propose a multiple object tracking system that has a concrete detection and tracking characteristics by using multi-lateral histogram and SIFT feature extraction algorithm. Especially, by limiting the matching area to object's inside and by utilizing the location informations in the keypoint matching process of SIFT algorithm, we advanced the tracking performance for multiple objects. Based on the experimental results, we found that the proposed tracking system has a robust tracking operation in the complicated environments that multiple objects are frequently overlapped in various of directions.

Isolated Power Supply for Multiple Gate Drivers using Wireless Power Transfer System with Single-Antenna Receiver

  • Lim, Chang-Jong;Park, Shihong
    • Journal of Power Electronics
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    • v.17 no.5
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    • pp.1382-1390
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    • 2017
  • This paper presents a power supply for gate drivers, which uses a magnetic resonance wireless power transfer system. Unlike other methods where multiple antennas are used to supply power for the gate drivers, the proposed method uses a single antenna in an insulated receiver to make multiple mutually isolated power supplies. The power transmitted via single antenna is distributed to multiple power supplies for gate drivers through resonant capacitors connected in parallel that also block DC bias. This approach has many advantages over other methods, where each gate driver needs to be supplied with power using multiple receiver antennas. The proposed method will therefore lead to a reduction in production costs and circuit area. Because the proposed circuit uses a high resonance frequency of 6.78 MHz, it is possible to implement a transmitter and a receiver using a small-sized spiral printed-circuit-board-type antenna. This paper used a single phase-leg circuit configuration to experimentally verify the performance characteristics of the proposed method.

Affecting Factors on Performance of Preceptors and Preceptees (프리셉터와 프리셉티의 간호 업무성과 영향요인)

  • Yang, Nan-Young;Yoo, In-Ja;Han, Sung-Suk
    • The Journal of Korean Academic Society of Nursing Education
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    • v.11 no.2
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    • pp.135-141
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    • 2005
  • Purpose: This study was to investigate the factors influencing performance of preceptors and preceptees. Method: The selectees were composed of 27 preceptors and 27 preceptees. The preceptors were given twenty six hours of education and training concerned with theory and practice and then the preceptors mentioned above gave the preceptees vis-a-vis education and training for four weeks. The data were collected through a questionnaire survey of general characteristics, performance, autonomy, empowerment, organizational commitment. The data were analyzed using t-test, ANOVA, Pearson's correlation coefficient, and the Stepwise multiple Regression. Results: The differences of performance, autonomy, organizational commitment and empowerment were found to have a significance between preceptors and preceptees in preceptorship. The performance was significantly correlated between autonomy, organizational commitment and empowerment of the preceptors and preceptees. Stepwise multiple Regression analysis for performance revealed that the most powerful predictor was empowerment. These variables accounted for 37.7%(preceptors) and 54.6%(preceptees) of variance of the performance. Conclusion: The findings above indicated that the preceptorship was significant as nursing management intervention to increase nurses' performance. Therefore it may be necessary further to develop and apply, such as performance, autonomy, empowerment, organizational commitment in preceptorship.

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